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CVE-2026-41067

CVE-2026-41067 · Astro: XSS via incomplete `</script>` sanitization in `define:vars` allows case-insensitive and whitespace-based bypass

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Astro is a web framework. Prior to 6.1.6, the defineScriptVars function in Astro's server-side rendering pipeline uses a case-sensitive regex /<\/script>/g to sanitize values injected into inline <script> tags via the define:vars directive. HTML parsers close <script> elements case-insensitively and also accept whitespace or / before the closing >, allowing an attacker to bypass the sanitization with payloads like </Script>, </script >, or </script/> and inject arbitrary HTML/JavaScript. This vulnerability is fixed in 6.1.6.

CVSS 6.1 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • astro

    Versions
    • < 6.1.6: Affected

    No fix published

  • astro npm

    Affected ranges
    • SEMVER: < 6.1.6

    Update to 6.1.6

Original sources

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